DESCRIPTION The C++ and Java languages provide function
overloading, which means that you can write many functions
with the same name, providing that each function takes
parameters of different types. In order to be able to
distinguish these similarly named functions C++ and Java
encode them into a low-level assembler name which uniquely
identifies each different version. This process is known as
mangling. The c++filt [1] program does the inverse mapping:
it decodes (demangles) low-level names into user-level names
so that they can be read.

Every alphanumeric word (consisting of letters, digits,
underscores, dollars, or periods) seen in the input is a
potential mangled name. If the name decodes into a C++ name,
the C++ name replaces the low-level name in the output,
otherwise the original word is output. In this way you can
pass an entire assembler source file, containing mangled
names, through c++filt and see the same source file
containing demangled names.

You can also use c++filt to decipher individual symbols
by passing them on the command line:

c++filt <symbol>

If no symbol arguments are given, c++filt reads symbol
names from the standard input instead. All the results are
printed on the standard output. The difference between
reading names from the command line versus reading names
from the standard input is that command line arguments are
expected to be just mangled names and no checking is
performed to separate them from surrounding text. Thus for
example:

c++filt -n _Z1fv

will work and demangle the name to "f()"
whereas:

c++filt -n _Z1fv,

will not work. (Note the extra comma at the end of the
mangled name which makes it invalid). This command however
will work:

echo _Z1fv, | c++filt -n

and will display "f(),", i.e., the demangled
name followed by a trailing comma. This behaviour is because
when the names are read from the standard input it is
expected that they might be part of an assembler source file
where there might be extra, extraneous characters trailing
after a mangled name. For example:

.type _Z1fv, @function

OPTIONS -_ --strip-underscore On some systems, both the
C and C++ compilers put an underscore in front of every
name. For example, the C name "foo" gets the low-
level name "_foo". This option removes the initial
underscore. Whether c++filt removes the underscore by
default is target dependent.

-n --no-strip-underscore Do not remove the initial
underscore.

-p --no-params When demangling the name of a function,
do not display the types of the functions parameters.

-t --types Attempt to demangle types as well as function
names. This is disabled by default since mangled types are
normally only used internally in the compiler, and they can
be confused with non- mangled names. For example, a function
called "a" treated as a mangled type name would be
demangled to "signed char".

-i --no-verbose Do not include implementation details
(if any) in the demangled output.

-s format --format=format c++filt can decode various
methods of mangling, used by different compilers. The
argument to this option selects which method it uses:

"auto" Automatic selection based on executable
(the default method)

"gnu" the one used by the GNU C++ compiler
(g++)

"lucid" the one used by the Lucid compiler
(lcc)

"arm" the one specified by the C++ Annotated
Reference Manual

"hp" the one used by the HP compiler (aCC)

"edg" the one used by the EDG compiler

"gnu-v3" the one used by the GNU C++ compiler
(g++) with the V3 ABI.

"java" the one used by the GNU Java compiler
(gcj)

"gnat" the one used by the GNU Ada compiler
(GNAT).

--help Print a summary of the options to c++filt and
exit.

--version Print the version number of c++filt and
exit.

@file Read command-line options from file. The options
read are inserted in place of the original @file option. If
file does not exist, or cannot be read, then the option will
be treated literally, and not removed.

Options in file are separated by whitespace. A
whitespace character may be included in an option by
surrounding the entire option in either single or double
quotes. Any character (including a backslash) may be
included by prefixing the character to be included with a
backslash. The file may itself contain additional @file
options; any such options will be processed recursively.

FOOTNOTES 1. MS-DOS does not allow "+"
characters in file names, so on MS-DOS this program is named
CXXFILT.

Permission is granted to copy, distribute and/or modify
this document under the terms of the GNU Free Documentation
License, Version 1.3 or any later version published by the
Free Software Foundation; with no Invariant Sections, with
no Front-Cover Texts, and with no Back-Cover Texts. A copy
of the license is included in the section entitled "GNU
Free Documentation License".